The present invention relates to protocol analysis, and more particularly to a device for analyzing digital data which are formulated in accordance with a communication protocol.
Particularly in protocol measurement technology, the coding, decoding and analysis of digital data plays a central role, involving the examination of so-called Protocol Data Units (PDUs) by computer software and the extraction of the information they contain. Because of the great variety of protocol types and special cases, there are a correspondingly large number of variants of decoder software required for this purpose. Such decoder software reflects the specific structure of a protocol. It contains elements which control the program sequence by evaluating the data contained in a PDU, and generates a decoder output. The software particularly searches sequentially for parameters in a given PDU to unequivocally identify such parameters and to qualify contents. A decoder output is generated from the data contained in the PDUs and from the program data contained in a memory.
The disadvantage of this method, which is known from the state of the art, is that the processing of the programs for protocol decoding is very time-consuming because, regardless of the process or platform selected, a large number of command cycles have to be processed. This involves loading the protocol elements to be decoded from a RAM into a processor register. The universal data path of the processor and the inventory of commands available with it allow the manipulation of the protocol data. Accordingly, decoder results are also moved via processor commands into a target area of the RAM. Because of the quantity of data generated and the high processing speed required, PDU decoding in real time is not possible with a software decoder. Owing to the necessary storage operations and bit manipulations, program processing is too slow for this purpose when considering the quantity of parameters to be processed.
What is desired is to provide a device and/or a method for analyzing digital data formulated in accordance with a communication protocol which allows a higher processing speed than the method known from the state of the art.